This project is designed to optimize and extend the ultrathin coating technology demonstrated in the Phase I project, which is aimed at facile, cost-effective, and broadly applicable thin-film coatings for the passivation of biosensor and medical device surfaces. Prevention of non-specific binding of proteins and other biomolecules is important for a large variety of biomaterial, optical, electrical and structural surfaces which suffer fouling (protein and cellular adhesion, microbial proliferation, and pore plugging) from functioning in contact with physiological fluids and pharmaceuticals. A new class of block copolymer reagents was prepared and demonstrated to provide self-assembled monolayers which can be photochemically fixed on the surface. After spontaneous formation from aqueous coating fluid, the monolayer film on the hydrophobic surface is stabilized through covalent attachment to the surface and in situ polymerization or crosslinking of diblock polymer molecules. The resulting "field of grass" from the hydrophilic block inhibits biomolecule adsorption and can provide attachment sites for desired biomolecules such as heparin. This Phase II effort will synthesize improved test models of this new class of multifunctional self-assembling monolayer molecules. "Living polymerization" will be used to prepare these photoreactive macromer surfactants, which will be use-tested on distal protection screens and hemodialysis membranes. PROPOSED COMMERCIAL APPLICATION: This effort is expected to provide new reagents and coating methodology for distal protection devices (thrombi collection screens) and hemodialysis membranes. Almost one million patients need hemodialysis three times per week. These coatings would provide reduced fouling and increased flux for microporous medical devices. The proposed work will also extend the block copolymer technology to alternate polymer backbones for increased lubricity and to biomolecule immobilization for increased hemocompatibility, providing better coatings for a variety of medical devices.